攻防线（Line of scrimmage），是加拿大式足球与美式足球比赛过程中的一条场地假想线，用以在新一波进攻行动开始前，区隔攻击方与防守方的球员。

攻防线实际上是平行于达阵线的两条直线，一条与球的前端切齐，另一条与球的后端切齐，两条线中间的狭长地带称为「中立区」。在美式足球比赛中，防守方球员站在靠近己方的攻防线之后即可；但在加拿大式足球比赛中，防守方球员至少要距离攻防线一码以上。

In American and Canadian football, a line of scrimmage is an imaginary transverse line (across the width of the football field) beyond which a team cannot cross until the next play has begun. Its location is based on the spot where the ball is placed after the end of the most recent play and following the assessment of any penalty yards.